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3 years ago

1. How is the modern periodic table organized?

Chemistry

1 answer:

Dimas [21]3 years ago

3 0

1. How is the modern periodic table organized? Increasing atomic number

2. What information about an atom's properties can you read from the periodic table? Metal or not metal. Does it want to gain or lose electrons

3. How are the relationships of elements in a group different from the relationships of elements in a period? a group will have similar properties A period will have different properties

4. Would you expect Strontium (Sr) to be more like potassium (K) or bromine (Br)?

potassium

5. Barium (Ba) is in Group 2. Recall that atoms in Group 1 lose one electron to form ions with a 1+ charge. What type of ion does barium form? Ba+2

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An "empty" container is not really empty if it contains air. How may moles of nitrogen are in an "empty" two-liter cola bottle a

Lisa [10]

Answer:

1. 0.0637 moles of nitrogen.

2. The partial pressure of oxygen is 0.21 atm.

Explanation:

1. If we assume ideal behaviour, we can use the Law of ideal gases to find the moles of nitrogen, considering that air composition is mainly nitrogen (78%), oxygen (21%) and argon (1%):

$V_{N_2}=V_{T}\times 0.78=2L \times 0.78 =1.56 L\\PV=nRT\\n_{N_2}=\frac{PV}{RT}=\frac{1 atm\times 1.56 L}{0.0821\frac{atmL}{molK}\times 298 K}\\n_{N_2}= 0.0637 mol$

2. Now, in order to find he partial pressure of oxygen we need to find the total moles of air, and then the moles of oxygen. Then, we use these results to determine the molar fraction of oxygen, to multiply it with total pressure and get the partial pressure of oxygen as follows:

$n_{total}=\frac{1 atm \times 2L}{0.0821 \frac{atmL}{molK}298K}=0.0817 mol$

$V_{O_2}=2L \times 0.21 = 0.42 L\\n_{O_2}=\frac {1atm \times 0.42 L}{0.0821 \frac{atm L}{mol K}298 K}=0.0172 mol\\X_{O_2}=\frac{n_{O_2}}{n_{total}}=\frac{0.0172 mol}{0.0817 mol}= 0.21$

$P_{O_2}=X_{O_2} \times P = 1 atm \times 0.21 = 0.21 atm$

As you see, the molar fraction and volume fraction are the same because of the assumption of ideal behaviour.

3 0

2 years ago

If we have equal masses of copper at 80oC and water at 20oC and we put them together, what is the final temperature?

Ket [755]

Answer:

The final temperature will be close to 20°C

Explanation:

First of all, the resulting temperature of the mix can't be higher than the hot substance's (80°C) or lower than the cold one's (20°C). So options d) and e) are imposible.

Now, due to the high heat capacity of water (4,1813 J/mol*K) it can absorb a huge amount of heat without having a great increment in its temperature. On the other hand, copper have a small heat capacity (0,385 J/mol*K)in comparison.

In conclusion, the copper will release its heat decreasing importantly its temperature and the water will absorb that heat resulting in a small increment of temperature. So the final temperature will be close to 20°C

<u>This analysis can be done because we have equal masses of both substances. </u>

6 0

3 years ago

What is a substance's melting point?

TEA [102]

A melting point of a substance is a point at which the sample or substance start converting in liquid. For most substances, melting and freezing points are approximately equal. For example, the melting point and freezing point of mercury is 234.32 kelvins (−38.83 °C or −37.89 °F). Hope this helped!! :)

5 0

2 years ago

Read 2 more answers

CN- is a Bronsted - Lowry base. What will this substance form when it accepts a proton?

sergejj [24]

It will form HCN Hydrogen Cyanide.

8 0

2 years ago

The whole reason things stay afloat or sink is because water is

mars1129 [50]

Answer:

I think the density of the object determines if it floats or sinks

5 0

2 years ago